Biological samples, such as substances in solution, e.g. blood samples, water tests, and tissue samples such as fertilized embryos, can often be effectively stabilized by freezing. The frozen fluid and/or sample will remain stable for extended periods of time as long as it is kept in the frozen state. Frequently these samples are collected in relatively large quantities, or collective sample, but could be utilized in smaller quantities, or specimens e.g. for test purposes.
When a specimen is needed, it often requires thawing of the entire collective sample to obtain the specimen currently needed, and then refreezing the remainder of the collective sample. However, frequent freezing and thawing cycles are almost always detrimental to the often unstable ingredients in the collective sample.
One solution is to store the collective sample in multiple small individual vessels. Then, when a specimen is needed, the necessary number of individual vessels may be thawed to provide the specimen needed without thawing and refreezing other individual samples of the collective sample. However, separation and freezing in individual vessels is cumbersome and time consuming, requires a larger amount of individual vessels, and thus larger storage facilities. The chance of confusion and mix-up of the individual vessels is also present.
WO 2004/042341 discloses a cryo preservation device and method for providing a collective vessel with individual, partial samples in the same cryo tube, separated by a gas-filled free space. This method and device provides excellently separated, well defined specimens, but requires investments in complex filling machinery using specified pressures, adjusted to the type and viscosity of the sample fluid.
U.S. Pat. No. 6,383,453 discloses a multi-aliquot storage vessel and corresponding break tool, where the vessel is provided with a number of equally distanced breakpoints, comprising of ring-shaped “notches” that extend around the perimeter of the vessel, and corresponding interior double ring-formed protrusions. One embodiment comprises external screw threads for closure caps, which threads are provided until a distance above and below said breakpoints. The break tool comprises an upper and a lower cylindrical part for housing each end of the vessel to be broken, which parts are provided with lips for abutment against the non-threaded parts of the vessel during breakage. The disclosed vessel may be difficult to manufacture in e.g. plastic or glass materials due to the provision of the internal protrusions. The disclosed break tool, when breaking a vessel as disclosed, must be positioned very carefully to avoid holding on to the treads in order to provide a clean break at the break points provided. This may prove difficult, when the second part is applied to the vessel too.
Accordingly, there is a need for a breakable storage vessel and break tool for breaking such vessel, which alleviate the above problems of the known vessels and tools.